Overview
EN ISO 22476-12:2009 - Geotechnical investigation and testing - Field testing - Part 12: Mechanical cone penetration test (CPTM) specifies the procedures, equipment requirements and reporting for the mechanical cone penetration test (CPTM). The standard covers pushing a cone penetrometer into the ground at a constant rate, recording cone penetration resistance and, where applicable, sleeve friction and total penetration force. CPTM results support soil-profile interpretation, soil classification and estimation of geotechnical parameters such as density, shear strength and deformation/consolidation characteristics.
Keywords: EN ISO 22476-12:2009, CPTM, mechanical cone penetration test, cone penetration resistance, geotechnical investigation, field testing, in situ tests.
Key Topics and Technical Requirements
- Equipment requirements: cone penetrometer assembly (cone, optional friction sleeve), push rods/inner rods, thrust machine, measuring system and calibration/maintenance procedures.
- Measured parameters: cone penetration resistance, sleeve friction, total penetration resistance and penetration length/depth.
- Test types & classes: distinction of CPTM test types and application classes; selection of appropriate equipment and procedures for site conditions.
- Execution procedures:
- Constant-rate pushing of the cone penetrometer.
- Use of friction reducers where required.
- Continuous vs discontinuous logging of forces and penetration.
- Positioning and levelling of the thrust machine; reference to datum for ground surface elevation.
- Quality assurance: equipment checks, routine calibration, tolerances and surface-roughness considerations for probes.
- Reporting: required information on test location (relative to reproducible reference point), penetration depth/length, recorded and calculated parameters, and presentation formats for test results.
Applications
- Determination of subsurface stratification and soil type profiling.
- Input for estimating soil density, shear-strength parameters, and deformation or consolidation characteristics.
- Comparative assessment alongside other in situ tests (e.g., SPT, dynamic probing).
- Commonly used in site investigations for foundations, earthworks, tunnels and ground improvement feasibility.
Who Should Use This Standard
- Geotechnical engineers and site investigation teams performing CPTM in situ testing.
- Contractors supplying CPTM equipment and measurement systems.
- Laboratories and consultants preparing geotechnical investigation reports.
- Designers and specifiers requiring standardized, repeatable field test data.
Related Standards
- EN 1997-1 / EN 1997-2 (geotechnical design and investigation planning) - planning and evaluation of investigation programmes.
- ISO 10012 (measurement management) and ISO 8503 (surface roughness) - referenced for measurement and equipment surface requirements.
EN ISO 22476-12:2009 provides the technical framework for reliable mechanical cone penetration testing, ensuring consistent in situ data for geotechnical assessment and design.
